The Mechanical Handling and Storing of Material

GRAVITY BUCKET CONVEYORS 133 have to be negotiated there must be a second pair of rails above the wheels to guard against derailment. The axles are provided with sufficient lubricant to last for several months. The pitch of the buckets—being necessarily large for these conveyors—influences the dimensions of the driving drum, which must be larger than that of other conveyors of the tipping bucket type. As the buckets must be some distance apart, to allow sufficient freedom when going round curves, it was necessary to have a special feeding device. This consists of an outlet controlled by a valve which opens automatically every time a bucket presents itself beneath it, and as the buckets can be set further apart for elevators of small Fig. 179. Portion of Continuous Bucket Conveyor. capacity, the opening of this slide can be set to suit any pitch of buckets. On the other hand, should a higher capacity subsequently be required in any installation, the buckets can be set closer together, and thus the filling machine is correspondingly altered to suit the pitch of the buckets. Such intermittent feeding devices present no difficulty for small material, but for large coal they would be a decided hindrance to the efficiency of the conveyor. (This applies to all conveyors where the buckets are not close together.) These buckets are emptied in a similar manner to those of the conveyors already described. This conveyor is reported to be successfully at work in several boiler-house installations, as well as for coaling locomotive engines. It is built in six sizes for gauges of 20, 24, 28, 32, 36, and 40 in., with a capacity for each bucket of I to I cwt. of coal. The buckets are placed at a pitch of 20, 30, 40, and 50 in., and it is claimed that a capacity of over 100 tons per hour can be reached. It is said that the speed of this conveyor can be varied from 30 to 100 ft. per minute. There seems, however, no apparent reason why this particular conveyor should run faster than any other swinging bucket conveyor, to which type it closely conforms. It is built by the Humboldt Engineering Works Co., of Cologne. The Schenck Conveyor.—This is shown in Fig. 182. It differs in many